I've done a direct drive modification for the E3D Titan Extruder with a V6 Hotend (https://www.thingiverse.com/thing:1744154) and I've also done a direct drive modification for the Flexion E3D Retrofit Kit for V6 Hotend(https://www.thingiverse.com/thing:1934066). Neither have imposed any limitation on speed or build area as far as I can tell. I did switch to a pancake stepper on the E3D Titan direct drive modification to reduce ringing.

Yeah I've been using a direct titan (switching to aero later today) and have not noticed any issues with quality at speed. I suspect it would make a difference at extreme speeds but then I'm not planning to go that fast. I was printing at 140mm/s with this setup as a test for someone and it was printing fairly well.

QuotePDBeal
I've done a direct drive modification for the E3D Titan Extruder with a V6 Hotend (https://www.thingiverse.com/thing:1744154) and I've also done a direct drive modification for the Flexion E3D Retrofit Kit for V6 Hotend(https://www.thingiverse.com/thing:1934066). Neither have imposed any limitation on speed or build area as far as I can tell. I did switch to a pancake stepper on the E3D Titan direct drive modification to reduce ringing.

QuoteDjDemonD
Yeah I've been using a direct titan (switching to aero later today) and have not noticed any issues with quality at speed. I suspect it would make a difference at extreme speeds but then I'm not planning to go that fast. I was printing at 140mm/s with this setup as a test for someone and it was printing fairly well.